Light-emitting diode (LED) is widely applied to optical display apparatus, traffic lights, data storage apparatus, communication apparatus. lighting apparatus, and medical equipment. As shown in FIG. 7, a conventional LED comprises an n-type semiconductor layer 1104, an active layer 1106, and a p-type semiconductor layer 1108 sequentially formed on a substrate 1102. Portions of the p-type semiconductor layer 1108 and the active layer 1106 are removed to expose a portion of the n-type semiconductor layer 1104. A p-type electrode a1 and an n-type electrode a2 are formed on the p-type semiconductor layer 1108 and the n-type semiconductor layer 1104 respectively. Because the n-type electrode a2 requires a sufficient surface for following process such as wire bonding, a substantial portion of the active layer 1106 has to be removed and the light extraction efficiency is therefore lowered.
Furthermore, the LED described above can be connected with other devices to form a light-emitting apparatus. FIG. 6 illustrates a diagram of a conventional light-emitting apparatus. As shown in FIG. 6, a light-emitting apparatus 1200 comprises a sub-mount 1202 having an electrical circuit 1204; a solder 1206 formed on the sub-mount 1202 to adhere the LED 1210 to the sub-mount 1202, and electrically connecting a substrate 1212 of the LED 1210 and the electrical circuit 1204 of the sub-mount 1202; and an electrical connecting structure 1208 electrical connecting an electrode 1214 of the LED 1210 and the electrical circuit 1204 of the sub-mount 1202, wherein the sub-mount 1202 can be a lead frame or a large scaled mounting substrate suitable for the design of the electrical circuit of the light-emitting apparatus and improving heat dissipation.